big wheel vs commanding officer

big wheel

noun
  • A person with a great deal of power or influence, especially a high-ranking person in an organization. 

  • A Ferris wheel. 

  • A low-riding tricycle with a large front wheel. 

commanding officer

noun
  • The officer in command of, and typically having ultimate authority over, a military unit. 

How often have the words big wheel and commanding officer occurred in a corpus of books? (source: Google Ngram Viewer )